1. Field of the Invention
The present invention relates to a high frequency power amplifier which makes it possible to improve the operating efficiency over a wide output power range.
2. Background Art
High frequency power amplifiers that amplify high frequency signals are used for cellular phones and portable terminals. Conventionally, a route in a high frequency power amplifier suitable for large power output operation is used to obtain large power output of 27.5 dBm and a route suitable for medium power output operation is used to obtain medium power output of 17 dBm, and operating efficiency at respective levels of output power is thereby improved (e.g., see Proceedings of the 36th European Microwave Conference, P 348-P 351).